公开(公告)号：US08760201B1

公开(公告)日：2014-06-24

申请号：US13793438

申请日：2013-03-11

Applicant: Analog Devices Technology

Inventor： Ting Gao ,  Jiefeng Yan

IPC: H03L7/06

CPC classification number: H03L7/0895

Abstract: Systems and methods for capacitance multiplication using one charge pump for a phase lock loop employ a digital controlled loop filter that operates in a time division mode. Embodiments of the loop filter block the current from the charge pump according to the digital control, such that the charge pump cannot charge or discharge the integral capacitor when the digital control is enabled. Because at least a portion of the current is blocked, it takes more time for the charge pump to charge or discharge the capacitor to a certain level. The capacitor then appears to be larger than its actual value with respect to operation of the phase lock loop.

Abstract translation: 使用一个用于锁相环的电荷泵进行电容倍增的系统和方法采用以时分模式工作的数字控制环路滤波器。 环路滤波器的实施例根据数字控制阻挡来自电荷泵的电流，使得当数字控制被使能时，电荷泵不能对积分电容器充电或放电。 因为电流的至少一部分被阻塞，所以电荷泵将电容器充电或放电到一定水平需要更多的时间。 相对于锁相环的操作，电容器似乎大于其实际值。